Process of treating hydrocarbon oil.



R. H. BROWNLEE.

PROCESS OF TREATING HYDROCARBON OILS.

APPLICATION FILED MAR. 29.1917- Patented July 1, 1919.

ROY H. BROWNLEE, OF PITTSBURGH, PENNSYLVANIA.

PROCESS OF TREATING HYDROCARBON OILS.

. Specification of Letters Patent.

Patented July 1., 1919.

Application filed March 29, 1917. Serial No. 158,165.

a process in which a hydrocarbon oil may' be so treated as to crack thesame and obtain therefrom a yield of low boiling products,

such as commercial gasolene, which is either much higher than thepercentage of such products naturally contained in the oii undergoingtreatment or is formed wholly by the breaking up of the heavierhydrocarbons. A further object of the invention is to provide a processwhich is continuous and which is adapted for the cracking of hydrocarbon oils of varying boiling paint and density to obtain a maximumyield of the low boiling liquid hydrocarbons constitut ing commercialgasolene, without excessive formation of permanent gases and carbon. Astill further object of the invention is to provide a .process of suchnature that the objects above stated are obtained by subjecting thehigher boiling or heavier components of the oil to a continuouslyrecurrent treatment, under conditions favorable for the cracking of thesame, in the presence of a continuously decreased quantity of the vaporsof the lower boiling hydrocarbons formed in the normal operation of theprocess.

The theory of operation of the present process depends upon the factthat the operation of cracking petroleum and its derivatives constituteswhat is essentially a reversible chemical re-action. That is, when acertain proportion of the naturally contained heavier components of thepetroleum have undergone a molecular splitting or cracking to formlighter or lower boiling products the re-action normally reaches a stateof equilibrium due to the concentration of these products, so that achange of conditions, such as increased temperature, sufli;- cient tocause a continuance of the action will also result in an increasedproduction of undesired end products. In the present process, however,the conditions are such that the vapors condensable into the liquidhydrocarbon products desired may be continuously withdrawn from thesystem, while the heavier components are retained for a furthertreatment under conditions in which there is a lessened concentration ofthe vaporized products into which they are to be decomposed. Generallystated the present process consists in introducing oil and a suitablegas, preferably superheated steam or a hydrocarbon gas, into a pipesystem maintained at a temperature and pressure suitable for crackingthe hydrocarbon oil undergoing treatment; this pipe system bemg soconstructed and the process so conducted that vapors condensable intoliquids or" a predetermined gravity and boiling point are continuouslywithdrawn from the system, while the heavier components which arecarried by the gas are deposited in a liquid state throu hout the lengthof the pipe, and flow bac l iwardly therethrough so that they aresubjected to a further cracking in the presence of a lesserconcentration of the desired products than at the point of theirseparation.

In the accompanying drawings, Figure 1 is a diagrammatic plan Viewillustrating generally apparatus for conductingthe processof theinvention; Fig. 2 is a vertical sectional view of the apparatus; andFig. 3 is a detail view illustrating a modification for introducing bothsteam and a hydrocarbon gas into the pipe systems of the apparatus.

The general arrangement of the apparatu illustrated comprises a furnace1 having therein one or more units or pipe systems 2 extendingvertically thereof, a plurality of such units being shown throughout assuch re-duplication is desirable for purposes of operating economy. Eachof the units 2 is connected by suitable means with a steam line 3leading from a boiler 4 and with an oil line 5 leading from an oilreservoir 6 and having therein a suitable pressure pump 7. As shown,each of the units 2 is connected at its discharge end to a suitableheader or vapor line 8 leading to a water cooled condenser 9. In theirpreferred form, each of the units, or pipe systems, comprises aplurality of sections 10 which are vertically inclined and suitablysupported in the furpace, and which are welded or otherwise suitablyconnected at their contiguous ends so as to form a continuous pipehaving elbows 11, at each of which the horizontal direction in which thepipe extends is changed. At the lower extremity of the pipe is a steaminjector 12 which, as shown, connects with a steam header 13 whichsupplies the injector of eachof the pipes and which receives steam fromthe superheating coil 14 which lies beneath the floor of the furnace andforms a continuatiOn of the steam line 3. In the elbow 11 immediatelyabove the steam injector is located the oil inlet '15 to which leads anoil pipe 16 receiving oil from a line 5 under pressure of the pump 7Adjacent the lower extremity of the pipeis located the drain pipe 18 forthe withdrawal of residuum settling in this portion of the pipe.

In order to regulate the steam used, the steam line 3 is provided with avalve 19 and pressure gage 20, while a valve 21 is also provided in theconnection 22 from the steam header to the injector 12. In order toregulate the inflow of oil each of the oil pipes 16 leading from the oilline 5 to each of the units is provided with an oil meter 23 and a valveor cook 24. The valve 25 and pressure gage 26 are located in the vaporline between the furnace and the condenser, and a valve 27 is placed inthe outlet from the condenser, so that the pressure in the pipe systemsmay be uniformly regulated,

and the vaporized products condensed either under substantiallyatmospheric pressure or under higher pressure as may be desired.Pyrometer connections 28 are also provided in the uppermost sections ofeach of the pipe system 2 so that the temperature of each of the systemsmay be observed and the temperature desired may be uniformly maintained.

In conducting the process, the furnace is first fired to raise the pipesystems to a suitable temperature. This temperature naturally varieswith the grade of oil to be treated, but is in each instance such aswould be more than sufiicient to vaporize substanti'ally all thevaporizable components of the particular oil undergoing treatment ifsuch vaporization were to take place under atmospheric pressure merely.

This definition of the temperature may be illustrated by taking crudepetroleum as an example. In such case, if the crude petroleum is of sucha grade that all its components,'disregarding residual tars or cokes,will pass over in the 4 form of vapor during ordinary distillation at atemperature of 800 degrees Fahrenheit,

.the temperature maintained in a pipe system employing the presentprocess must be in excess of 800 degrees Fahrenheit; a temperature offrom 800 degr'eesto 1200 degrees Fahrenheit being employed. A suitablevapor or gas is then allowed to flow through the pipes to expel air andbuild up a slight initial pressure in the system. If steam is used it ispreferably superheated to a temperature of approximately 350 degreesFahrenheit in order to increase the velocity of its passage through'thepipes. The inflow of oil is then started, and this is at first almostcompletely and immediately vaporized and serves to build up a highpressure withing the system, this pressure being regulated by means ofeither of the pressure regulating valves 25 and 27 and being preferablymaintained in excess of five atmospheres.

As the operation proceeds a certain proportion of the oil as originallyintroduced will not be immediately vaporized, because of the existinghigh pressure, and will flow backwardly in a film on the walls of thepipe sections 10 lying below the oil inlet 15. This film of oil will besubjected during its passage to a cracking temperature and pressure, andsuccessive portions, or components thereof will be continuouslyvaporized into vapors such as may be condensed to form products of thedesired low boiling point and specific gravity, these vapors beingcarried forwardly through the system by the current of steam or gastherein. Also a certain proportion of the components of the oil which isoriginally carried on through the pipe system will separate out duringits passage, such separated components being those which are notsusceptible of cracking under the conditions of pressure, temperature,and concentration of the oil vapors caused by previous cracking,existing at the point of their separation. These components also flowcontinuously downward through the pipe system counter to the current ofsteam or gas therein and are gradually cracked as they reach points atwhich the concentration of the products previously cracked isincreasingly less. During the entire operation the temperature, the rateof oil inflow, and the speed of the carrying gases may be so regulatedthat the composition of the vapors leaving the discharge ends of thepipe systems is maintained substantially uniform.

As illustrated in the drawings, the connections are arranged to utilizesuperheated steam as the gas which is to act as a carrier for the oil.The process may, however, be performed with a suitable permanent gasintroduced into the pipe system under pressure, with or without theadditional use of steam. This permanent gas is preferably a hydrocarbongas, such as natural gas or the permanent gases formed during theoperation of the process, since such gases serve to increase theconcentration of the gaseous end products throughout the length of thesystem, and thus tend to prevent the continuance of the crackingoperation beyond the point at which the resulting products arecondensable. relatively inactive chemically, under the conditions of theprocess, such as superheated steam, is used, the gas used serves toprevent undue decomposition by conveying the vaporized portions of theoil throughithe system at a fair rate of speed, and also serves in somedegree to modify the effect of the high temperature to which the oil issubjected.

In conducting the process it is possible to use both steam and apermanent gas, such as the hydrocarbon gases above mentioned, and thussecure the effect of both upon the oil undergoing treatment. Fig. 3 ofthe drawings illustrates a connection arranged to introduce steam, oil,and a permanent gas into the pipe systems. As illustrated, thesuperheated steam is introduced into the lower extremity of thelowermost pipe section by means identical. with those illustrated inFigs. 1 and 2 of the drawings, previously described. The oil isalsointroduced at the elbow next above the steam inlet, as in thepreviously'described construction, but a special connection is providedfor introducing the permanent gas together with the oil. Thisarrangement comprises an injector 29 to which lead the oil pipe 16 and agas pipe 29 leading from any suitable source of gas supply maintainedunder pressure. By means of this arrangement the 011 is atomized by thegas and is introduced with it in a commingled current,

so that the full effect of the gas in preventing undue decompositionofthe oil is ob tained. With such connections the oil may be introducedmerely under pressure, and

steam alone used for the carrying current, or a permanent gas may beintroduced, in addition to the steam, either continuously throughout thetime oftreatment or intermittently, as the operator may desire.

Due to the conditions above described the process is capable of crackinga relatively great proportion ofthe material undergoing treatment into alower boiling product, such proportion depending somewhat upon thenature of the material. run. For in stance with a kerosene distillatethe ield of commercial gasolene is extremely igh,

while with a petroleum residuum from which the naturally occurringlighter components of the petroleum have been removed the gasolene yieldwould be decreased. ln any case however, a relatively high percentage ofthe vaporizable components of the material submitted to treatment areconverted into condensable low boiling products without an excessiveformation of carbon or of permanent gas. The process is continuous sothat re-treatment of the heavier components takes place during thecontinuous introduction of new ma- In case a gas which is ing a carryingcurrent of terial without the necessity of drawing off such heaviercomponents and re-treating them by a separate operation.

The process is obviously not limited to the size, form or arrangement ofthe means used for carrying it out, since a variety of forms or shapesof pipe might be arranged to, form pipe systems suitable for the processdescribed. The arrangement of plant shown is merely general, and isillustrative of one only of a wide range of alternative devices andarrangements.

' What I claim is 1. The process of treating hydrocarbon oils toincrease the yield of low boiling point liquid products, which consistsin introducing a carrying current of gas adjacent the lower extremity ofa vertically extending pipe system heated and maintained. underpressure, introducing the oil below the upper extremity of said pipesystem, continuously separating the heavier components from the lightervaporized products, and permitting a continuous reflux of the formerthrough the system counter to the current of gas introduced thereinto sothat the heavier components separated at any point in the system undergoa further treatextremity of said pipe system, continuously separatingthe heavler components from the lighter vaporized products, andpermitting a continuous reflux of the former through the system counterto the current of gas introduced thereinto so that the heaviercomponents separated at any point in the system undergo a furthertreatment in the presence of a lesser concentration of the lighterproducts than at the point of their separation.

3. The process of treating hydrocarbon oils to increase the yield of lowboiling point liquid products, which consists in introducgas adjacentthe lower extremity of a vertically extending pipe system maintained ata temperature in excess of 800 degrees Fahrenheit and under a pressurein excess of five atmospheres, introducing the oil below the upperextremity of said pipe system, continuously separating the heaviercomponents of the oil from the lighter vaporized products, and,permitting a continuous reflux of the former through the system counterto the current of gas introduced thereinto so that the heaviercomponents separated at any point in the system undergo a furthertreatment in the resence of a lesser concentration of the lig tervaporized products than at the point of their separation. v

4. The process of treating hydrocarbon oils to increase the yield of lowboiling point ual particles of oil from the current of gas and of thevapors formed, whereby every particle of oil may be subjected torepeated treatment at oints in the system containing a lesserconcentration of-the products into which the oil is to be converted thanat the point of its separation.

5. The process of treating hydrocarbon oils to increase the yield of lowboiling point liquid. products, which consists in continuouslyintroducing a currentof gas at a point adjacent the lower extremity of avertically extending pipe system arranged to permit passage of the samethroughout the length thereof, introducing the oil to be treated intosaid pipe system below the upper extremity thereof, maintaining saidsystem throughout its length under pressure and at a temperature inexcess of that required to vaporize substantially all the vaporizablecomponents of the oil at atmospheric pressure, and permitting a repeatedseparati'on and reflux of individual particles of oil jfrom the currentof gas and of the vapors formed, whereby every particle of oil may besubjected to repeated treatment at points in v the system containing alesser concentration of the products into which the oil is to beconverted than at the point of its separation.

6. The process of treating hydrocarbon oils to increase the yield of lowboiling point liquid products, which consists in introducing steamadjacent the lower extremity of a vertically extending pipe systemheated and maintained under ressure, introducing the oil and a hydrocaron'gas below the upper extremity of said pipe system; continuouslyseparating out the .heavier components from the lighter vaporizedproducts, and withdrawin the latterand permitting a reflux of the ormerthrough the system so that the heavier components undergo a furthertreattially all the vaporizable components of the oil at atmosphericpressure, introducing the oil and a hydrocarbon gas below the upperextremity of said pipe system; continuously separating the heaviercomponents from the lighter vaporized products, and permitting a refluxof the former through the system so that the heavier componentsseparated at any point in the system undergo a further treatment in thepresence of a lesser concentration of the lighter products than at thepoint of their separation.

8. The process of treating hydrocarbon oils to increase the yield of lowboiling point liquid products, which consists in introducing steamadjacent the lower extremity of a vertically extending pipe systemmaintained at a. temperature in excess of 800 degrees Fahrenheit andunder a pressure in excess of five atmospheres, introducingthe oil and ahydrocarbon gas below theupper extremity of said pipe system;continuously separating the heavier components of the oil from thelighter vaporized products and permitting a reflux of the formerthrough-the system so that the heavier components separated at any pointin the system undergo a further treatment in the resence of a lesserconcentration of the lighter vaporized products than at the point oftheir -separation.

9. The process of treating hydrocarbon oils to increase the yield of lowboiling liquid products, which consists in introducing ROY H. BROWNLEE.

Witnesses:

WALTER S. KLEMANSKI, Sun B. FRITZ.

